A Syrian family has been arrested after a mother attempted to smuggle her 23-year-old son from a Greek island to the mainland in a suitcase.

The woman had been given the right to move around freely inside Greece after applying for asylum, but her two sons, 23 and 24, had not, the Athens News Agency reported on Friday.

The family had previously arrived on the island of Lesvos after crossing the Aegean Sea by boat, and had been staying at the Moria camp, which has been plagued by heavy snows, fires and refugee deaths.

After receiving international protection cards, asylum seekers are permitted to leave the islands and travel to the Greek mainland while their claims are heard.

The mother and her older son – who had not been given the right to travel around freely – attempted to board a ferry bound for the Athens port of Piraeus on Thursday evening.

Guards at the port, suspicious about the size and weight of one of the pair’s suitcases, opened it to find the woman’s younger son curled up inside, the Athens News Agency reported.

All three were subsequently arrested and returned to the camp at Moria.

A deal struck between the European Union and Turkey in March 2016 prevents asylum seekers who arrive at the islands from travelling on to the mainland, leaving thousands of people stuck in camps on the islands.

With camps severely overcrowded, increasing numbers of people are reportedly attempting to travel to the mainland without the correct documentation, hiding in trucks and cars before they board the ferries that leave for the mainland on a daily basis.

Last Saturday, a man attempted to board a ferry by climbing across the rope that connected the boat to the harbour.